Dynamic holography non-scanning printing device

ABSTRACT

A printing device ( 106 ) includes a dynamic holography printing application configured to generate a laser control signal and a LCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator) control signal based on a two-dimensional content corresponding to a lithography mask. A laser source ( 110 ) generates a plurality of incident laser beams based on the laser control signal. A LCOS-SLM ( 112 ) modulates the plurality of incident laser beams based on the LCOS-SLM control signal, generates a plurality of holographic wavefronts ( 214,216 ), each holographic wavefront forming at least one corresponding focal point. The LCOS-SLM generates a plurality of distinct focused light field regions ( 506,508,510 ) at interference points of focal points of the plurality of holographic wavefronts. The plurality of distinct focused light field regions correspond to the two-dimensional content.

This application is a national stage application under 35 U.S.C. § 371of International Application No. PCT/GB2016/054042, filed Dec. 22, 2016,which claims priority to U.S. Provisional Patent Application No.62/273,019, filed Dec. 30, 2015, the disclosures of which are explicitlyincorporated by reference herein.

FIELD

The present disclosure relates to a device and method. Morespecifically, the present disclosure relates to a printer and method ofprinting. Yet more specifically, the present disclosure relates to aholographic printer and a method of printing using holographicprojection. Some embodiments relate to a holographic projector forheating a target surface and a method of heating a target surface usingholographic projection. Some embodiments relate to a holographicprojector for curing a target surface and a method of curing a targetsurface using holographic projection.

BACKGROUND

3D printing refers to various processes used to synthesize athree-dimensional object. In 3D printing, successive layers of materialare formed under computer control to create a three-dimensional physicalobject. These objects can be of almost any shape or geometry, and areproduced from a 3D model or other electronic data source. Unfortunately,3D printing can take a very long time because only one layer can beprinted at a time and mechanical scanning introduces risk of printingerrors, including misalignment and poor precision.

There is described herein apparatus, methods and systems for heating—oreven curing—a target surface using a holographic projection system.

Light scattered from an object contains both amplitude and phaseinformation. This amplitude and phase information can be captured on,for example, a photosensitive plate by well-known interferencetechniques to form a holographic recording, or “hologram”, comprisinginterference fringes. The hologram may be reconstructed by illuminationwith suitable light to form a two-dimensional or three-dimensionalholographic reconstruction, or replay image, representative of theoriginal object.

Computer-generated holography may numerically simulate the interferenceprocess. A computer-generated hologram, “CGH”, may be calculated by atechnique based on a mathematical transformation such as a Fresnel orFourier transform. These types of holograms may be referred to asFresnel or Fourier holograms. A Fourier hologram may be considered aFourier domain representation of the object or a frequency domainrepresentation of the object. A CGH may also be calculated by coherentray tracing or a point cloud technique, for example.

A CGH may be encoded on a spatial light modulator, “SLM”, arranged tomodulate the amplitude and/or phase of incident light. Light modulationmay be achieved using electrically-addressable liquid crystals,optically-addressable liquid crystals or micro-mirrors, for example.

The SLM may comprise a plurality of individually-addressable pixelswhich may also be referred to as cells or elements. The light modulationscheme may be binary, multilevel or continuous. Alternatively, thedevice may be continuous (i.e. is not comprised of pixels) and lightmodulation may therefore be continuous across the device. The SLM may bereflective meaning that modulated light is output from the SLM inreflection. The SLM may equally be transmissive meaning that modulatedlight is output from the SLM is transmission.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

To easily identify the discussion of any particular element or act, themost significant digit or digits in a reference number refer to thefigure number in which that element is first introduced.

FIG. 1 a block diagram illustrating an example of a dynamic holographyprinting device in accordance with one example embodiment.

FIG. 2 a block diagram illustrating another example of a dynamicholography printing device in accordance with one example embodiment.

FIG. 3 a block diagram illustrating an example of a dynamic holographyprinting device in accordance with another example embodiment.

FIG. 4 a block diagram illustrating an example of a printing operationusing a dynamic holography printing device in accordance with oneexample embodiment.

FIG. 5 a block diagram illustrating an example of three-dimensionalprinted object in accordance with one example embodiment.

FIG. 6 is a diagram illustrating a cross-section of an example of aLCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator).

FIG. 7 is a flow diagram illustrating one example operation of a dynamicholography printing device, in accordance with an example embodiment.

FIG. 8 is a flow diagram illustrating another example operation of adynamic holography printing device, in accordance with an exampleembodiment.

FIG. 9 is a flow diagram illustrating another example operation of adynamic holography printing device, in accordance with an exampleembodiment.

FIG. 10 a block diagram illustrating components of a machine, accordingto some example embodiments, able to read instructions from amachine-readable medium and perform any one or more of the methodologiesdiscussed herein.

SUMMARY

Example methods and systems are directed to a dynamic holographyprinting device. Examples merely typify possible variations. Unlessexplicitly stated otherwise, structures (e.g., structural components,such as modules) are optional and may be combined or subdivided, andoperations (e.g., in a procedure, algorithm, or other function) may varyin sequence or be combined or subdivided. In the following description,for purposes of explanation, numerous specific details are set forth toprovide a thorough understanding of example embodiments. It will beevident to one skilled in the art, however, that the present subjectmatter may be practiced without these specific details.

Dynamic holographic wavefronts can be generated and manipulated suchthat the constructive and destructive interference of the laser lightscan be controlled precisely and across a three-dimensional spatial area.With sufficient energy, these constructive and destructive interferencepoints have enough energy to generate heat. The location and intensityof the heat can be controlled using the constructive and destructiveinterference at the laser wavefronts to focus and precisely route themodulated light (e.g., a single beam) in a three-dimensional space toprint a three-dimensional object using traditional 3D printinglithography/sintering techniques.

This approach allows for the generated wavefront(s) to be used tosimultaneously print an entire “layer” of a 3D object without requiringany mechanical or spatial scanning of the material surface. Thisholographic layer acts like a lithography “mask”, but focuses dynamiclaser light as the mask, instead of relying on static mechanicalblocking of the light as in a traditional physical mask. The followingdescribes an example embodiment of a printer device using holographictechniques.

The printer device uses a laser light that is diffracted (and,optionally, reflected) through a holographic spatial light modulator(e.g. a LCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator)system). LCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator) isused to modulate the phase or amplitude of the laser light in order togenerate a holographic wavefront (that is, a wavefront whichreconstructs—e.g. on a surface—to form a holographic reconstruction orholographic image). The phase of the modulated light is controlled insuch a manner that a holographic wavefront can be generated, optionally,forming multiple focal points or just a single focal point. The phase ofthe modulated light may be controlled in such a manner to form aholographic image having any configuration. That is, the LCOS-SLMredistributes the receive optical energy in accordance with the LCOS-SLMcontrol signal. As may be understood from the present disclosure, thereceive optical energy may be focused to, for example, at least onefocal point. Constructive and destructive interference from multipleholographic wavefronts occur at the focal points, leading to aconcentration of energy from the laser light. The concentrated energyheats up or cures a material at the surface layer of a target material(e.g., heat sensitive paper). Because the focal points are generated bywaveform reconstruction, the pattern and location of the focal pointscan be very precisely controlled to create complex patterns and shapesby modulating the phase and/or amplitude of the laser light. In someembodiments, the SLM is an LCOS-SLM. The LCOS-SLM thus allows a user tosteer the holographic fields changing the location of the interferencepattern.

In some embodiments, a device may include a hardware processor; a lasersource configured to generate a group of incident laser beams based onthe laser control signal; and/or a LCOS-SLM configured to receive thegroup of incident laser beams, to modulate the group of incident laserbeams based on the LCOS-SLM control signal, to generate a group ofholographic wavefronts, each holographic wavefront forming at least onecorresponding focal point, to generate a group of distinct focused lightfield regions based on the interference points of the focal points ofthe group of holographic wavefronts, the group of distinct focused lightfield regions corresponding to the two-dimensional content, and to curethe layer of the target material.

There is provided a device comprising: a hardware processor comprising adynamic holography printing application configured to generate a lasercontrol signal and a LCOS-SLM (Liquid Crystal on Silicon Spatial LightModulator) control signal based on two-dimensional content; a lasersource configured to generate a plurality of incident laser beams basedon the laser control signal; and a LCOS-SLM configured to receive theplurality of incident laser beams, to modulate the plurality of incidentlaser beams based on the LCOS-SLM control signal, to generate aplurality of holographic wavefronts from the modulated plurality ofincident laser beams, each holographic wavefront having a correspondingfocal point, to generate a plurality of distinct focused light fieldregions based on the interference points of the focal points of theplurality of holographic wavefronts, the plurality of distinct focusedlight field regions corresponding to the two-dimensional content formedon a layer of a target material, and to cure the layer of the targetmaterial.

In some embodiments, the hardware processor may include a dynamicholography printing application configured to generate a laser controlsignal and a LCOS-SLM (Liquid Crystal on Silicon Spatial LightModulator) control signal based on a two-dimensional contentcorresponding to a lithography mask.

In some embodiments, such a device may further include a laser sourcecontroller coupled to the laser source, the laser source controllerconfigured to receive the laser control signal and to control the lasersource in response to the laser control signal and/or a LCOS-SLMcontroller coupled to the LCOS-SLM, the LCOS-SLM controller configuredto receive the LCOS-SLM control signal and to control the LCOS-SLM inresponse to the LCOS-SLM control signal.

In some embodiments, the LCOS-SLM is configured to focus laser light toat least one focal point. Curing may occur at the at least one focalpoint if the power density is sufficiently high. That is, in theseembodiments, interference of plural focal points is not required toachieve the required power density for curing.

In some embodiments, the LCOS-SLM is configured to receive first laserlight and second laser light. In some embodiments, the first laser lightis received on a first plurality of pixels of the SLM and the secondlaser light is received on a second plurality of pixels of the SLM. Insome embodiments, the first laser light and second laser light arereceived at the same time or substantially the same time. The firstplurality of pixels are configured to focus the first laser light to atleast one first focal point. The second plurality of pixels areconfigured to focus the second laser light to at least one second focalpoint. In some embodiments, the at least one first focal point and theat least one second focal point are substantially coincident. In theseembodiments, constructive interference occurs at the focal points andcuring of a target surface will occur if the power density issufficiently high. It may be understood that the pixels of the SLM maybe divided into any number of subsets, each subset arranged to receiverespective laser light and focus that respective laser light to at leastone focal point. In other embodiments, a plurality of SLMs may be usedto bring a corresponding plurality of laser light beams to a commondistinct focused light field regions to cure the target surface at thedistinct focused light field regions. In some embodiments, the dynamicholography printing application is configured to: identify a group ofpredefined spatial locations corresponding to the two-dimensionalcontent on the layer of the target material adjacent to the LCOS-SLM,generate the LCOS-SLM control signal and the laser control signal toadjust a position of the focal points of the modulated group of incidentlaser beams to correspond with the group of predefined spatiallocations, the LCOS-SLM curing the portion of the target material at theinterference points formed based on the group of predefined spatiallocations.

In some embodiments, the dynamic holography printing application isconfigured to: identify a first group of predefined spatial locationscorresponding to a first portion of the two-dimensional content in thetarget material adjacent to the LCOS-SLM, adjust the laser controlsignal and the LCOS-SLM control signal based on the first group ofpredefined spatial locations, and form a second group of the focalpoints of the group of modulated laser light beams based on the firstgroup of predefined spatial locations, the first portion of thetwo-dimensional content cured at the interference points based on thesecond group of focal points on the surface of the target material.

In some embodiments, the dynamic holography printing application isconfigured to: identify a second group of predefined spatial locationscorresponding to a second portion of the two-dimensional content in thetarget material, adjust the laser control signal and the LCOS-SLMcontrol signal based on the second group of predefined spatiallocations, form a third group of the focal points of the group ofmodulated laser light beams based on the second group of predefinedspatial locations, and form another set of interference points based onthe third group of focal points in addition to the interference pointsbased on the second group of focal points, the second portion of thetwo-dimensional content cured at the other set of interference points.

In some embodiments, the dynamic holography printing application isconfigured to: receive printing data corresponding to thetwo-dimensional content, identify areas on the surface of the targetmaterial based on the two-dimensional content, identify a second groupof focal points corresponding to the areas on the surface of the targetmaterial based on the two-dimensional content, and adjust the lasercontrol signal and the LCOS-SLM control signal based on the second groupof focal points, the areas on the surface of the target material curedat the interference points based on the second group of focal points.

In some embodiments, the dynamic holography printing application isconfigured to: receive printing data corresponding to thetwo-dimensional content, compute a group of locations of interferencepoints based on the two-dimensional content, calculate a group oflocations of focal points corresponding to the group of locations ofinterference points, generate the laser control signal and the LCOS-SLMcontrol signal to form holographic wavefronts based on the location ofthe group of locations of focal points corresponding to the group oflocations of interference points, heat the target material at the groupof locations of the interference points of the holographic wavefronts,and form the two-dimensional content at the heated portion of the targetmaterial.

In some embodiments, the LCOS-SLM is configured to modulate at least aphase or an amplitude of the group of laser light beams, and to generatethe group of holographic wavefronts which interfere at the focal points.

In some embodiments, such a device may further include a MEMS deviceconfigured to receive the group of incident laser beams from the lasersource and/or a MEMS controller configured to generate a MEMS controlsignal to the MEMS device, the MEMS device reflecting the group ofincident laser beams at a group of locations on the LCOS-SLM based onthe MEMS control signal, the LCOS-SLM configured to receive the group ofincident laser beams at the group of locations, to modulate the group ofincident laser beams at the group of locations, and to generate a secondgroup of holographic wavefronts from the modulated group of incidentlaser beams at the group of locations.

In some embodiments, each holographic wavefront forms at least onecorresponding focal point, and heat—even, to cure—a portion of thetarget material at the interference points of focal points of the secondgroup of holographic wavefronts. The modulated laser beams may include acombination of at least a spatially modulated phase-only light and aspatially modulated amplitude-only light.

In some embodiments, the LCOS-SLM is a reflective device. That is, theLCOS-SLM outputs spatially-modulated light in reflection. However, thepresent disclosure is equally applicable to a transmissive LCOS-SLM.

The term “hologram” is used to refer to the recording which containsamplitude and/or phase information about the object. The term“holographic reconstruction” is used to refer to the opticalreconstruction of the object which is formed by illuminating thehologram. The term “replay field” is used to refer to the plane in spacewhere the holographic reconstruction is formed. The terms “image” and“image region” refer to areas of the replay field illuminated by lightforming the holographic reconstruction.

Reference is made herein to “holographic wavefronts” with respect to thewavefront of spatially-modulated light formed by the spatial lightmodulator. The wavefront is described as being holographic because itgives rise to a holographic reconstruction in the replay field. In someembodiments, the holographic wavefront gives rise to a holographicreconstruction through interference at the replay field. In someembodiments, the spatial light modulator applies a spatially-variantphase-delay to the wavefront. Each incident laser beam therefore givesrise to a corresponding holographic wavefront. In some embodiments, theLCOS-SLM is configured to receive a plurality of incident laser beamsand output a respective plurality of holographic wavefronts.

Reference is also made herein to each holographic wavefront “formingfocal points” with respect to formation of the holographicreconstruction at the replay field. The term “focal points” refers tothe presence of concentrations of optical energy in the replay field.For example, each holographic wavefront may concentrate the light into aplurality of relatively small regions in the replay field. The term“focal” therefore merely reflects that the optical energy isconcentrated. The term “points” therefore merely reflects that theseareas of concentration may be plural and may be relatively small so asto achieve high energy density. For example, a received laser beam maybe concentrated, or focused, by the spatial light modulator to aplurality of points in the replay field.

With respect to operation of the SLM, the terms “encoding”, “writing” or“addressing” are used to describe the process of providing the pluralityof pixels of the SLM with a respect plurality of control values whichrespectively determine the modulation level of each pixel. It may besaid that the pixels of the SLM are configured to “display” a lightmodulation distribution in response to receiving the plurality ofcontrol values.

The term “light” is used herein in its broadest sense. Some embodimentsare equally applicable to visible light, infrared light and ultravioletlight, and any combination thereof.

Some embodiments describe 1D and 2D holographic reconstructions by wayof example only. In other embodiments, the holographic reconstruction isa 3D holographic reconstruction. That is, in some embodiments, eachcomputer-generated hologram forms a 3D holographic reconstruction.

Some embodiments refer to a laser by way of example only and the presentapplication is equally applicable to any light sources having sufficientoptical energy to heat and cure a target material—e.g. a 3D printingprecursor material—as described.

DETAILED DESCRIPTION OF DRAWINGS

It has been found that a holographic reconstruction of acceptablequality can be formed from a “hologram” containing only phaseinformation related to the original object. Such a holographic recordingmay be referred to as a phase-only hologram. Some embodiments relate tophase-only holography by way of example only. That is, in someembodiments, the spatial light modulator applies only a phase-delaydistribution to incident light. In some embodiments, the phase delayapplied by each pixel is multi-level. That is, each pixel may be set atone of a discrete number of phase levels. The discrete number of phaselevels may be selected from a much larger set of phase levels or“palette”.

In some embodiments, the computer-generated hologram is a Fouriertransform of the object for reconstruction. In these embodiments, it maybe said that the hologram is a Fourier domain or frequency domainrepresentation of the object. Some embodiments use a reflective SLM todisplay a phase-only Fourier hologram and produce a holographicreconstruction at a replay field, for example, a light receiving surfacesuch as a screen or diffuser.

A light source, for example a laser or laser diode, is disposed toilluminate the SLM 140 via a collimating lens. The collimating lenscauses a generally planar wavefront of light to be incident on the SLM.The direction of the wavefront is off-normal (e.g. two or three degreesaway from being truly orthogonal to the plane of the transparent layer).In other embodiments, the generally planar wavefront is provided atnormal incidence using a beam splitter, for example. In embodiments, thearrangement is such that light from the light source is reflected off amirrored rear surface of the SLM and interacts with a phase-modulatinglayer to form an exit wavefront. The exit wavefront is applied to opticsincluding a Fourier transform lens, having its focus at a screen.

The Fourier transform lens receives a beam of phase-modulated light fromthe SLM and performs a frequency-space transformation to produce aholographic reconstruction at the screen.

Light is incident across the phase-modulating layer (i.e. the array ofphase modulating elements) of the SLM. Modulated light exiting thephase-modulating layer is distributed across the replay field. Notably,in this type of holography, each pixel of the hologram contributes tothe whole reconstruction. That is, there is not a one-to-one correlationbetween specific points on the replay field and specificphase-modulating elements.

In these embodiments, the position of the holographic reconstruction inspace is determined by the dioptric (focusing) power of the Fouriertransform lens. In some embodiments, the Fourier transform lens is aphysical lens. That is, the Fourier transform lens is an optical Fouriertransform lens and the Fourier transform is performed optically. Anylens can act as a Fourier transform lens but the performance of the lenswill limit the accuracy of the Fourier transform it performs. Theskilled person understands how to use a lens to perform an opticalFourier transform. However, in other embodiments, the Fourier transformis performed computationally by including lensing data in theholographic data. That is, the hologram includes data representative ofa lens as well as data representing the image. It is known in the fieldof computer-generated hologram how to calculate holographic datarepresentative of a lens. The holographic data representative of a lensmay be referred to as a software lens. For example, a phase-onlyholographic lens may be formed by calculating the phase delay caused byeach point of the lens owing to its refractive index andspatially-variant optical path length. For example, the optical pathlength at the centre of a convex lens is greater than the optical pathlength at the edges of the lens. An amplitude-only holographic lens maybe formed by a Fresnel zone plate. It is also known in the art ofcomputer-generated hologram how to combine holographic datarepresentative of a lens with holographic data representative of theobject so that a Fourier transform can be performed without the need fora physical Fourier lens. In some embodiments, lensing data is combinedwith the holographic data by simple vector addition. In someembodiments, a physical lens is used in conjunction with a software lensto perform the Fourier transform. Alternatively, in other embodiments,the Fourier transform lens is omitted altogether such that theholographic reconstruction takes place in the far-field. In furtherembodiments, the hologram may include grating data—that is, dataarranged to perform the function of a grating such as beam steering.Again, It is known in the field of computer-generated hologram how tocalculate such holographic data and combine it with holographic datarepresentative of the object. For example, a phase-only holographicgrating may be formed by modelling the phase delay caused by each pointon the surface of a blazed grating. An amplitude-only holographicgrating may be simply superimposed on an amplitude-only hologramrepresentative of an object to provide angular steering of anamplitude-only hologram.

In some embodiments, the hologram is simply a software lens. That is,the software lens is not combined with other holographic data such asholographic data representative of an object. In some embodiments, thehologram includes a software lens and software grating arranged todetermine the spatial location of light focused by the software lens. Itmay be understood that the hologram can produce any desired light field.In some embodiments, a plurality of holographically-formed light fieldsare interfered—for example, constructively interfered—to form distinctfocused light field regions. It should therefore be understood thatbecause the spatial light modulator is dynamically reconfigurable withdifferent holograms, the distinct focused light field regions are undersoftware control. There is therefore provided a holographic system forcontrollably irradiating a target with at least one distinct focusedlight field region—e.g. a region of constructive interference havingrelatively high intensity—e.g. energy or power density.

A Fourier hologram of a desired 2D image may be calculated in a numberof ways, including using algorithms such as the Gerchberg-Saxtonalgorithm. The Gerchberg-Saxton algorithm may be used to derive phaseinformation in the Fourier domain from amplitude information in thespatial domain (such as a 2D image). That is, phase information relatedto the object may be “retrieved” from intensity, or amplitude, onlyinformation in the spatial domain. Accordingly, a phase-only Fouriertransform of the object may be calculated.

In some embodiments, a computer-generated hologram is calculated fromamplitude information using the Gerchberg-Saxton algorithm or avariation thereof. The Gerchberg Saxton algorithm considers the phaseretrieval problem when intensity cross-sections of a light beam,I_(A)(x, y) and I_(B)(x, y), in the planes A and B respectively, areknown and I_(A)(x, y) and I_(B)(x, y) are related by a single Fouriertransform. With the given intensity cross-sections, an approximation tothe phase distribution in the planes A and B, Ψ_(A)(x, y) and Ψ_(B)(x,y) respectively, is found. The Gerchberg-Saxton algorithm findssolutions to this problem by following an iterative process.

The Gerchberg-Saxton algorithm iteratively applies spatial and spectralconstraints while repeatedly transferring a data set (amplitude andphase), representative of I_(A)(x, y) and I_(B)(x, y), between thespatial domain and the Fourier (spectral) domain. The spatial andspectral constraints are I_(A)(x, y) and I_(B)(x, y) respectively. Theconstraints in either the spatial or spectral domain are imposed uponthe amplitude of the data set. The corresponding phase information isretrieved through a series of iterations.

In some embodiments, the hologram is calculated using an algorithm basedon the Gerchberg-Saxton algorithm such as described in British patent2,498,170 or 2,501,112 which are hereby incorporated in their entiretyby reference.

In some embodiments, there is provided a real-time engine arranged toreceive image data and calculate holograms in real-time using thealgorithm. In some embodiments, the image data is a video comprising asequence of image frames. In other embodiments, the holograms arepre-calculated, stored in computer memory and recalled as needed fordisplay on a SLM. That is, in some embodiments, there is provided arepository of predetermined holograms.

However, some embodiments relate to Fourier holography andGerchberg-Saxton type algorithms by way of example only. The presentdisclosure is equally applicable to Fresnel holography and hologramscalculated by other techniques such as those based on point cloudmethods.

The present disclosure may be implemented using any one of a number ofdifferent types of SLM. The SLM may output spatially modulated light inreflection or transmission. In some embodiments, the SLM is a liquidcrystal on silicon LCOS-SLM but the present disclosure is not restrictedto this type of SLM.

FIG. 1 is a block diagram illustrating an example of a dynamicholography printing device in accordance with one example embodiment. Adynamic holography printing device 106 includes a laser source 110, anLCOS-SLM 112, a holographic printing controller 102, a processor 114,sensors 104, and a storage device 108.

The laser source 110 generates a laser beam(s). The laser source 110directs the laser beam(s) towards the LCOS-SLM 112. The LCOS-SLM 112modulates the incident laser beam(s) (e.g., laser light from the lasersource 110) based on signal data from the processor 114 to generatedreflected light (e.g., modulated laser light). The modulated laser lightfrom the LCOS-SLM 112 forms holographic wavefronts. Heat is formed atthe constructive interference points of the holographic wavefronts. Theheat can be shaped, manipulated, steered by adjusting the modulation ofthe incident laser beams, the number of incident laser beams, and theintensity, size, and direction of the laser beams. The heat can be usedto cure specific areas on a surface of a target material fortwo-dimensional printing. That is, the shape of the heated area iscontrolled by controlling the hologram (or holograms) represented on thespatial light modulator. In some embodiments, the spatial lightmodulator is configured to provide at least one phase-only lens to bringthe received light to at least one corresponding focal point. In someembodiments, the spatial light modulator is configured to provide atleast one phase-only lens and at least one corresponding grating tocontrollably-position the corresponding focused light.

The holographic printing controller 102 generates a laser control signalto the laser source 110 and an LCOS-SLM 112 control signal to theLCOS-SLM 112 based on the pattern identified by the processor 114.

The processor 114 includes a dynamic holography printing application 118to control and steer regions of interference (e.g., heating regions).The dynamic holography printing application 118 identifies a printingpattern and location relative to a surface of the LCOS-SLM 112. Theprinting pattern and distance to the surface of the target material maybe user-selected or determined based on data from sensors 104.

In one example embodiment, the dynamic holography printing application118 identifies predefined spatial locations (e.g., areas) correspondingto the desired printing pattern (e.g., a two-dimensional content) in atarget material. The dynamic holography printing application 118generates the LCOS-SLM control signal and the laser control signal toadjust a position of the focal points of the modulated plurality ofincident laser beams to correspond with the predefined spatiallocations. The LCOS-SLM 112 modulates the laser light such that thewavefront interference generates energy (e.g., heat) at the interferencepoints based on the predefined spatial locations to form thetwo-dimensional content in the target material by curing thecorresponding areas.

In another example embodiment, the dynamic holography printingapplication 118 identifies a first set of predefined spatial locationsadjacent to the LCOS-SLM 112 and adjusts the laser control signal andthe LCOS-SLM control signal based on the first set spatial locations.The dynamic holography printing application 118 determines a set offocal points of the set of modulated laser light beams based on thefirst set of predefined spatial locations. The LCOS-SLM 112 forms thehigh intensity regions at the interference points based on the set offocal points of the set of modulated laser light beams.

In another example embodiment, the dynamic holography printingapplication 118 identifies another set of predefined spatial locationsand adjusts the laser control signal and the LCOS-SLM control signalbased on the other set of predefined spatial locations. The dynamicholography printing application 118 determines focal points of themodulated laser light beams based on the other set of predefined spatiallocations. The LCOS-SLM 112 changes the location of the distinct focusedlight field regions from the interference points based on the set offocal points to the interference points based on the focal points of themodulated laser light beams based on the other set of predefined spatiallocations.

In another example embodiment, the dynamic holography printingapplication 118 receives an identification of a spatial location andgeometric printing pattern based on a two-dimensional content (e.g., atwo-dimensional image). The dynamic holography printing application 118identifies a set of focal points corresponding to the identification ofthe spatial location and geometric printing pattern. The dynamicholography printing application 118 adjusts the laser control signal andthe LCOS-SLM control signal based on the set of focal points. Heat isgenerated at the interference points based on the set of focal points.

In another example embodiment, the dynamic holography printingapplication 118 receives an identification of a spatial location andgeometric pattern of the distinct focused light field regions andidentifies a set of interference points corresponding to theidentification of the spatial location and geometric printing pattern.The dynamic holography printing application 118 identifies a second setof focal points based on the set of interference points and adjusts thelaser control signal and the LCOS-SLM control signal based on the secondplurality of focal points. In some embodiments, plasma is formed at theinterference points based on the second set of focal points. In theseembodiments, the plasma is responsible for the localised heating.

In another example embodiment, the processor 114 retrieves from thestorage device 108 content associated with a physical object detected bysensors 104. In one example embodiment, the dynamic holography printingapplication 118 identifies a particular physical object (e.g., anidentifier such as a barcode) and generates a location and printingpattern (e.g., a 2D model of an electric circuit associated with theidentifier).

The sensors 104 include, for example, a thermometer, an infrared camera,a barometer, a humidity sensor, an EEG sensor, a proximity or locationsensor (e.g, near field communication, GPS, Bluetooth, Wifi), an opticalsensor (e.g., camera), an orientation sensor (e.g., gyroscope), an audiosensor (e.g., a microphone), or any suitable combination thereof. It isnoted that the sensors described herein are for illustration purposesand the sensors 104 are thus not limited to the ones described.

The storage device 108 stores an identification of the sensors and theirrespective functions. The storage device 108 further includes a databaseof visual references (e.g., images, visual identifiers, features ofimages) and corresponding geometric shape and patterns (e.g.,two-dimensional patterns that can be used to build electrical circuits).

In one embodiment, the dynamic holography printing device 106 maycommunicate over a computer network with a server to retrieve a portionof a database of visual references. The computer network may be anynetwork that enables communication between or among machines, databases,and devices (e.g., the dynamic holography printing device 106).Accordingly, the computer network may be a wired network, a wirelessnetwork (e.g., a mobile or cellular network), or any suitablecombination thereof. The computer network may include one or moreportions that constitute a private network, a public network (e.g., theInternet), or any suitable combination thereof.

Any one or more of the modules described herein may be implemented usinghardware (e.g., a processor of a machine) or a combination of hardwareand software. For example, any module described herein may configure aprocessor to perform the operations described herein for that module.Moreover, any two or more of these modules may be combined into a singlemodule, and the functions described herein for a single module may besubdivided among multiple modules. Furthermore, according to variousexample embodiments, modules described herein as being implementedwithin a single machine, database, or device may be distributed acrossmultiple machines, databases, or devices.

FIG. 2 is a block diagram illustrating another example of a dynamicholography printing device in accordance with one example embodiment.The dynamic holography printing device 106 includes the LCOS-SLM 112, anLCOS-SLM controller 202, the laser source 110, a laser controller 204, aholographic printing controller 102, and the processor 114 including thedynamic holography printing application 118.

The dynamic holography printing application 118 identifies a heat (orprinting) pattern and computes the location and patterns of theinterference points of holographic waves to form the heat pattern. Thedynamic holography printing application 118 communicates the locationand patterns of the interference points to the holographic printingcontroller 102. In another example embodiment, the dynamic holographyprinting application 118 computes the locations and patterns of theinterference points and generate a laser control signal and a LCOS-SLMcontrol signal to the holographic printing controller 102 based on thecomputed locations and patterns of the interference points.

The holographic printing controller 102 sends the laser control signalto the laser controller 204. The holographic printing controller 102also sends the LCOS-SLM control signal to the holographic printingcontroller 102. The laser controller 204 generates and communicates thelaser control signal to control an intensity, a number of beams, beamsize, and a beam direction of the laser source 110. The LCOS-SLMcontroller 202 generates and communicates the LCOS-SLM control signal todirect the LCOS-SLM 112 to modulate the laser light from the lasersource 110.

FIG. 2 illustrates the laser source 110 that produces a first incidentlaser beam and a second incident laser beam directed at the LCOS-SLM112. The LCOS-SLM 112 modulates the first incident laser beam into afirst set of holographic light field 214 (e.g., a first holographicwavefront) and the second incident laser beam into a second holographicwavefront second set of holographic light field 216 (e.g., a secondholographic wavefront). The constructive interference between the firstset of holographic light field 214 and the second set of holographiclight field 216 generates heat. The shape and location of the heat canbe controlled and steered by adjusting the control signals to the lasercontroller 204 and the LCOS-SLM controller 202.

FIG. 3 is a block diagram illustrating an example of a dynamicholography printing device in accordance with another exampleembodiment. The dynamic holography printing device 106 includes theLCOS-SLM 112, the LCOS-SLM controller 202, the laser source 110, thelaser controller 204, a MEMS device 302, a MEMS controller 304, and alaser controller 204.

The dynamic holography printing application 118 identifies a pattern andcomputes the location and patterns of the interference points ofholographic waves to form a two-dimensional content on a surface layerof the target 206. The dynamic holography printing application 118communicates the location and patterns of the interference points to theholographic printing controller 102.

The holographic printing controller 102 sends the laser control signalto the laser controller 204. The holographic printing controller 102also sends the LCOS-SLM control signal to the holographic printingcontroller 102. In one example embodiment, the holographic printingcontroller 102 sends a MEMS control signal to the MEMS controller 304.

The MEMS controller 304 communicates the MEMS control signal to the MEMSdevice 302 to control a direction of a laser beam from the laser source110. In one example embodiment, the MEMS controller 304 generates asynchronization signal to both the laser source 110 and the MEMS device302. The synchronization signal enables the MEMS device 302 to operateand reflect corresponding individual light beams from the laser source110.

The MEMS device 302 receives one or more laser beam from the lasersource 110 and reflects corresponding individual light beams to theLCOS-SLM 112. The MEMS device 302 reflects the light beams based on thesynchronization signal from the MEMS controller 304 or holographicprinting controller 102 to guide the corresponding individual lightbeams to the corresponding locations on the LCOS-SLM 112. The MEMSdevice 302 includes, for example, one or more mirrors. The position andorientation of the mirrors is controlled and adjusted based on thesynchronization signal received from the MEMS controller 304.

In other embodiments, the MEMS device is instead a second SLM deviceconfigured to direct the laser beams using a hologram—e.g. of agrating—as described herein.

FIG. 4 is a block diagram illustrating an example of a printingoperation using a dynamic holography printing device in accordance withone example embodiment. The dynamic holography printing application 118identifies a two-dimensional content and computes the location andpatterns of the interference points of holographic waves to form thetwo-dimensional content. The dynamic holography printing application 118communicates the location and patterns of the interference points to theholographic printing controller 102.

FIG. 4 illustrates a first incident laser beam and a second incidentlaser beam directed at the LCOS-SLM 112. The LCOS-SLM 112 modulates thefirst incident laser beam into a first set of holographic light field402 (e.g., a first holographic wavefront) and the second incident laserbeam into a second set of holographic light field 404 (e.g., a secondholographic wavefront). The constructive/destructive interference 406between the first set of holographic light field 402 and the second setof holographic light field 404 forms heat. The shape and location of theinterference 406 can be controlled and steered by adjusting the controlsignals to the laser controller 204 and the LCOS-SLM controller 202.

The dynamic holography printing device 106 can spatially tune theholographic light fields to interfere at multiple locations. Forexample, the target 206 includes curable or sinterable material thatsolidifies at the interference 406. The cure direction 408 indicatesthat the wavefronts can be adjusted such that the location ofcuring/sintering can be adjusted to allow for solidification at multiplepoints.

In another example embodiment, multiple areas of interferences (406,410, 412) may be formed simultaneously by generating multiple sets ofholographic light fields. The multiple areas of interferences formtwo-dimensional spatial region in a layer corresponding to thetwo-dimensional content.

FIG. 5 is a block diagram illustrating an example of three-dimensionalprinted object in accordance with one example embodiment. The dynamicholography printing application 118 generates multiples regionsholographic light fields (506, 508, 510) using the techniques previouslydescribed with respect to FIG. 4. The combined regions form the surfacelayer of the target material 502 to form a printed pattern 504.

FIG. 6 is a diagram illustrating a cross-section of an example of aLCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator). AnLCOS-SLM 628 is formed using a single crystal silicon substrate 616. Thesubstrate 616 consists of a two-dimensional array of square planaraluminium electrodes 612, spaced apart by a gap 618, arranged on theupper surface of the substrate 616. The electrodes 612 are connected tothe substrate 616 via a circuit 614 buried in the substrate 616. Eachelectrode 612 forms a respective planar mirror. The electrodes 612 maybe connected to the LCOS-SLM controller 626. In other words, theelectrodes 612 receives control signal from the LCOS-SLM controller 626.

An alignment layer 610 is disposed on top of the two-dimensional arrayof electrodes 612, and a liquid crystal layer 608 is disposed on thealignment layer 610.

A second alignment layer 606 is disposed on top of the liquid crystallayer 608. A planar transparent layer 602 (e.g. made of glass) isdisposed on the top of the second alignment layer 606. A singletransparent electrode 604 is disposed between the planar transparentlayer 602 and the second alignment layer 606.

Each of the square electrodes 612 defines, together with the overlyingregion of the transparent electrode 604 and the intervening liquidcrystal layer 608, a controllable phase-modulating element 624 (alsoreferred to as a pixel). The effective pixel area, or fill factor, isthe percentage of the total pixel which is optically active, taking intoaccount the space or gap 618 between pixels. By controlling the voltageapplied to each electrode 612 with respect to the transparent electrode604, the properties of the liquid crystal material (in the liquidcrystal layer 608) of the respective phase modulating element may bevaried. The variation of the phase modulating element provides avariable delay to incident light 620. The effect is to providephase-only modulation to the wavefront (i.e. no amplitude effect occursin the resulting modulated light 622).

One advantage of using a reflective LCOS spatial light modulator is thatthe liquid crystal layer can be half the thickness than would benecessary if a transmissive device were used. This greatly improves theswitching speed of the liquid crystal (a key point for projection ofmoving video images). Another advantage is that a LCOS device is alsocapable of displaying large arrays of phase only elements in a smallaperture. Small elements (typically approximately 10 microns or smaller)result in a practical diffraction angle (a few degrees) so that theoptical system does not require a very long optical path.

It is easier to adequately illuminate the small aperture (a few squarecentimeters) of the LCOS-SLM 628 than it would be for the aperture of alarger liquid crystal device. LCOS SLMs also have a large apertureratio, there being very little dead space between the pixels (becausethe circuitry to drive them is buried under the mirrors). The smallaperture results in lowering the optical noise in the replay field.

Another advantage of using a silicon backplane (e.g., silicon substrate616) has the advantage that the pixels are optically flat, which isimportant for a phase modulating device.

While embodiments relate to a reflective LCOS SLM, those of ordinaryskilled in the art will recognize that other types of SLMs can be usedincluding transmissive SLMs.

FIG. 7 is a flow diagram illustrating another example operation of adynamic holography printing device, in accordance with an exampleembodiment. At block 704, the dynamic holography printing application118 receives an identification of predefined spatial locations (e.g.,desired locations on a surface of a target material). At block 706, thedynamic holography printing application 118 computes the location ofinterference points of holographic wavefronts (to be generated by theLCOS-SLM 112) corresponding to the predefined spatial locations. Atblock 708, the dynamic holography printing application 118 calculatesthe location of focal points corresponding to the location ofinterference points of the holographic wavefronts. At block 710, thedynamic holography printing application 118 generates a laser controlsignal to the laser source 110 and a LCOS-SLM control signal to theLCOS-SLM 112 to form the holographic wavefronts based on the location offocal points.

FIG. 8 is a flow diagram illustrating another example operation of adynamic holography printing device, in accordance with an exampleembodiment. At block 804, the laser controller 204 generates a lasercontrol signal to the laser source 110 to control an intensity of alaser beam, a direction of a laser beam, and a number of laser beams. Atblock 806, the LCOS-SLM controller 202 generates a LCOS-SLM controlsignal to the LCOS-SLM 112 to control a modulation of incident lightbeams directed on the LCOS-SLM 112. At block 810, the LCOS-SLM 112modulates the incident laser beams from the laser source 110. At block812, the LCOS-SLM 112 forms holographic wavefronts from the modulatedlaser beams. At block 814, heat is generated at the location ofinterference points of the holographic wavefronts and the heat cures thetarget material at the corresponding heat locations.

FIG. 9 is a flow diagram illustrating another example operation of adynamic holography printing device, in accordance with an exampleembodiment. At block 904, the dynamic holography printing application118 receives printing data corresponding to a two-dimensional content(e.g., an image or an electric circuit pattern). At block 906, thedynamic holography printing application 118 computes a location of theinterference points inside the target material based on thetwo-dimensional content. At block 908, the dynamic holography printingapplication 118 calculates the location of focal points corresponding tothe location of the interference points. At block 910, the dynamicholography printing application 118 generates a laser control signal tothe laser source 110 and a LCOS-SLM control signal to an LCOS-SLM 112 toform holographic wavefronts based on the focal points.

FIG. 10 is a block diagram illustrating components of a machine 1000,according to some example embodiments, able to read instructions 1006from a computer-readable medium 1018 (e.g., a non-transitorymachine-readable medium, a machine-readable storage medium, acomputer-readable storage medium, or any suitable combination thereof)and perform any one or more of the methodologies discussed herein, inwhole or in part. Specifically, the machine 1000 in the example form ofa computer system (e.g., a computer) within which the instructions 1006(e.g., software, a program, an application, an applet, an app, or otherexecutable code) for causing the machine 1000 to perform any one or moreof the methodologies discussed herein may be executed, in whole or inpart.

In alternative embodiments, the machine 1000 operates as a standalonedevice or may be communicatively coupled (e.g., networked) to othermachines. In a networked deployment, the machine 1000 may operate in thecapacity of a server machine or a client machine in a server-clientnetwork environment, or as a peer machine in a distributed (e.g.,peer-to-peer) network environment. The machine 1000 may be a servercomputer, a client computer, a personal computer (PC), a tabletcomputer, a laptop computer, a netbook, a cellular telephone, asmartphone, a set-top box (STB), a personal digital assistant (PDA), aweb appliance, a network router, a network switch, a network bridge, orany machine capable of executing the instructions 1006, sequentially orotherwise, that specify actions to be taken by that machine. Further,while only a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines that individually orjointly execute the instructions 1006 to perform all or part of any oneor more of the methodologies discussed herein.

The machine 1000 includes a processor 1004 (e.g., a central processingunit (CPU), a graphics processing unit (GPU), a digital signal processor(DSP), an application specific integrated circuit (ASIC), aradio-frequency integrated circuit (RFIC), or any suitable combinationthereof), a main memory 1010, and a static memory 1022, which areconfigured to communicate with each other via a bus 1012. The processor1004 contains solid-state digital microcircuits (e.g., electronic,optical, or both) that are configurable, temporarily or permanently, bysome or all of the instructions 1006 such that the processor 1004 isconfigurable to perform any one or more of the methodologies describedherein, in whole or in part. For example, a set of one or moremicrocircuits of the processor 1004 may be configurable to execute oneor more modules (e.g., software modules) described herein. In someexample embodiments, the processor 1004 is a multicore CPU (e.g., adual-core CPU, a quad-core CPU, or a 128-core CPU) within which each ofmultiple cores behaves as a separate processor that is able to performany one or more of the methodologies discussed herein, in whole or inpart. Although the beneficial effects described herein may be providedby the machine 1000 with at least the processor 1004, these samebeneficial effects may be provided by a different kind of machine thatcontains no processors (e.g., a purely mechanical system, a purelyhydraulic system, or a hybrid mechanical-hydraulic system), if such aprocessor-less machine is configured to perform one or more of themethodologies described herein.

The machine 1000 may further include a video display 1008 (e.g., aplasma display panel (PDP), a light emitting diode (LED) display, aliquid crystal display (LCD), a projector, a cathode ray tube (CRT), orany other display capable of displaying graphics or video). The machine1000 may also include an alphanumeric input device 1014 (e.g., akeyboard or keypad), a cursor control device 1016 (e.g., a mouse, atouchpad, a trackball, a joystick, a motion sensor, an eye trackingdevice, or other pointing instrument), a drive unit 1002, a signalgeneration device 1020 (e.g., a sound card, an amplifier, a speaker, aheadphone jack, or any suitable combination thereof), and a networkinterface device 1024.

The drive unit 1002 (e.g., a data storage device) includes thecomputer-readable medium 1018 (e.g., a tangible and non-transitorymachine-readable storage medium) on which are stored the instructions1006 embodying any one or more of the methodologies or functionsdescribed herein. The instructions 1006 may also reside, completely orat least partially, within the main memory 1010, within the processor1004 (e.g., within the processor's cache memory), or both, before orduring execution thereof by the machine 1000. Accordingly, the mainmemory 1010 and the processor 1004 may be considered machine-readablemedia (e.g., tangible and non-transitory machine-readable media). Theinstructions 1006 may be transmitted or received over a computer networkvia the network interface device 1024. For example, the networkinterface device 1024 may communicate the instructions 1006 using anyone or more transfer protocols (e.g., hypertext transfer protocol(HTTP)).

In some example embodiments, the machine 1000 may be a portablecomputing device (e.g., a smart phone, tablet computer, or a wearabledevice), and have one or more additional input components (e.g., sensorsor gauges). Examples of such input components include an image inputcomponent (e.g., one or more cameras), an audio input component (e.g.,one or more microphones), a direction input component (e.g., a compass),a location input component (e.g., a global positioning system (GPS)receiver), an orientation component (e.g., a gyroscope), a motiondetection component (e.g., one or more accelerometers), an altitudedetection component (e.g., an altimeter), a biometric input component(e.g., a heartrate detector or a blood pressure detector), and a gasdetection component (e.g., a gas sensor). Input data gathered by any oneor more of these input components may be accessible and available foruse by any of the modules described herein.

As used herein, the term “memory” refers to a machine-readable mediumable to store data temporarily or permanently and may be taken toinclude, but not be limited to, random-access memory (RAM), read-onlymemory (ROM), buffer memory, flash memory, and cache memory. While thecomputer-readable medium 1018 is shown in an example embodiment to be asingle medium, the term “machine-readable medium” should be taken toinclude a single medium or multiple media (e.g., a centralized ordistributed database, or associated caches and servers) able to storeinstructions. The term “machine-readable medium” shall also be taken toinclude any medium, or combination of multiple media, that is capable ofstoring the instructions 1006 for execution by the machine 1000, suchthat the instructions 1006, when executed by one or more processors ofthe machine 1000 (e.g., processor 1004), cause the machine 1000 toperform any one or more of the methodologies described herein, in wholeor in part. Accordingly, a “machine-readable medium” refers to a singlestorage apparatus or device, as well as cloud-based storage systems orstorage networks that include multiple storage apparatus or devices. Theterm “machine-readable medium” shall accordingly be taken to include,but not be limited to, one or more tangible and non-transitory datarepositories (e.g., data volumes) in the example form of a solid-statememory chip, an optical disc, a magnetic disc, or any suitablecombination thereof. A “non-transitory” machine-readable medium, as usedherein, specifically does not include propagating signals per se. Insome example embodiments, the instructions 1006 for execution by themachine 1000 may be communicated by a carrier medium. Examples of such acarrier medium include a storage medium (e.g., a non-transitorymachine-readable storage medium, such as a solid-state memory, beingphysically moved from one place to another place) and a transient medium(e.g., a propagating signal that communicates the instructions 1006).

Certain example embodiments are described herein as including modules.Modules may constitute software modules (e.g., code stored or otherwiseembodied in a machine-readable medium or in a transmission medium),hardware modules, or any suitable combination thereof. A “hardwaremodule” is a tangible (e.g., non-transitory) physical component (e.g., aset of one or more processors) capable of performing certain operationsand may be configured or arranged in a certain physical manner. Invarious example embodiments, one or more computer systems or one or morehardware modules thereof may be configured by software (e.g., anapplication or portion thereof) as a hardware module that operates toperform operations described herein for that module.

In some example embodiments, a hardware module may be implementedmechanically, electronically, hydraulically, or any suitable combinationthereof. For example, a hardware module may include dedicated circuitryor logic that is permanently configured to perform certain operations. Ahardware module may be or include a special-purpose processor, such as afield programmable gate array (FPGA) or an ASIC. A hardware module mayalso include programmable logic or circuitry that is temporarilyconfigured by software to perform certain operations. As an example, ahardware module may include software encompassed within a CPU or otherprogrammable processor. It will be appreciated that the decision toimplement a hardware module mechanically, hydraulically, in dedicatedand permanently configured circuitry, or in temporarily configuredcircuitry (e.g., configured by software) may be driven by cost and timeconsiderations.

Accordingly, the phrase “hardware module” should be understood toencompass a tangible entity that may be physically constructed,permanently configured (e.g., hardwired), or temporarily configured(e.g., programmed) to operate in a certain manner or to perform certainoperations described herein. Furthermore, as used herein, the phrase“hardware-implemented module” refers to a hardware module. Consideringexample embodiments in which hardware modules are temporarily configured(e.g., programmed), each of the hardware modules need not be configuredor instantiated at any one instance in time. For example, where ahardware module includes a CPU configured by software to become aspecial-purpose processor, the CPU may be configured as respectivelydifferent special-purpose processors (e.g., each included in a differenthardware module) at different times. Software (e.g., a software module)may accordingly configure one or more processors, for example, to becomeor otherwise constitute a particular hardware module at one instance oftime and to become or otherwise constitute a different hardware moduleat a different instance of time.

Hardware modules can provide information to, and receive informationfrom, other hardware modules. Accordingly, the described hardwaremodules may be regarded as being communicatively coupled. Where multiplehardware modules exist contemporaneously, communications may be achievedthrough signal transmission (e.g., over suitable circuits and buses)between or among two or more of the hardware modules. In embodiments inwhich multiple hardware modules are configured or instantiated atdifferent times, communications between such hardware modules may beachieved, for example, through the storage and retrieval of informationin memory structures to which the multiple hardware modules have access.For example, one hardware module may perform an operation and store theoutput of that operation in a memory (e.g., a memory device) to which itis communicatively coupled. A further hardware module may then, at alater time, access the memory to retrieve and process the stored output.Hardware modules may also initiate communications with input or outputdevices, and can operate on a resource (e.g., a collection ofinformation from a computing resource).

The various operations of example methods described herein may beperformed, at least partially, by one or more processors that aretemporarily configured (e.g., by software) or permanently configured toperform the relevant operations. Whether temporarily or permanentlyconfigured, such processors may constitute processor-implemented modulesthat operate to perform one or more operations or functions describedherein. As used herein, “processor-implemented module” refers to ahardware module in which the hardware includes one or more processors.Accordingly, the operations described herein may be at least partiallyprocessor-implemented, hardware-implemented, or both, since a processoris an example of hardware, and at least some operations within any oneor more of the methods discussed herein may be performed by one or moreprocessor-implemented modules, hardware-implemented modules, or anysuitable combination thereof.

Moreover, such one or more processors may perform operations in a “cloudcomputing” environment or as a service (e.g., within a “software as aservice” (SaaS) implementation). For example, at least some operationswithin any one or more of the methods discussed herein may be performedby a group of computers (e.g., as examples of machines that includeprocessors), with these operations being accessible via a network (e.g.,the Internet) and via one or more appropriate interfaces (e.g., anapplication program interface (API)). The performance of certainoperations may be distributed among the one or more processors, whetherresiding only within a single machine or deployed across a number ofmachines. In some example embodiments, the one or more processors orhardware modules (e.g., processor-implemented modules) may be located ina single geographic location (e.g., within a home environment, an officeenvironment, or a server farm). In other example embodiments, the one ormore processors or hardware modules may be distributed across a numberof geographic locations.

Throughout this specification, plural instances may implementcomponents, operations, or structures described as a single instance.Although individual operations of one or more methods are illustratedand described as separate operations, one or more of the individualoperations may be performed concurrently, and nothing requires that theoperations be performed in the order illustrated. Structures and theirfunctionality presented as separate components and functions in exampleconfigurations may be implemented as a combined structure or componentwith combined functions. Similarly, structures and functionalitypresented as a single component may be implemented as separatecomponents and functions. These and other variations, modifications,additions, and improvements fall within the scope of the subject matterherein.

Some portions of the subject matter discussed herein may be presented interms of algorithms or symbolic representations of operations on datastored as bits or binary digital signals within a memory (e.g., acomputer memory or other machine memory). Such algorithms or symbolicrepresentations are examples of techniques used by those of ordinaryskill in the data processing arts to convey the substance of their workto others skilled in the art. As used herein, an “algorithm” is aself-consistent sequence of operations or similar processing leading toa desired result. In this context, algorithms and operations involvephysical manipulation of physical quantities. Typically, but notnecessarily, such quantities may take the form of electrical, magnetic,or optical signals capable of being stored, accessed, transferred,combined, compared, or otherwise manipulated by a machine. It isconvenient at times, principally for reasons of common usage, to referto such signals using words such as “data,” “content,” “bits,” “values,”“elements,” “symbols,” “characters,” “terms,” “numbers,” “numerals,” orthe like. These words, however, are merely convenient labels and are tobe associated with appropriate physical quantities.

Unless specifically stated otherwise, discussions herein using wordssuch as “accessing,” “processing,” “detecting,” “computing,”“calculating,” “determining,” “generating,” “presenting,” “displaying,”or the like refer to actions or processes performable by a machine(e.g., a computer) that manipulates or transforms data represented asphysical (e.g., electronic, magnetic, or optical) quantities within oneor more memories (e.g., volatile memory, non-volatile memory, or anysuitable combination thereof), registers, or other machine componentsthat receive, store, transmit, or display information. Furthermore,unless specifically stated otherwise, the terms “a” or “an” are hereinused, as is common in patent documents, to include one or more than oneinstance. Finally, as used herein, the conjunction “or” refers to anon-exclusive “or,” unless specifically stated otherwise.

What is claimed is:
 1. A holographic printer comprising: a hardwareprocessor comprising a dynamic holography printing applicationconfigured to generate a laser control signal and a LCOS-SLM (LiquidCrystal on Silicon Spatial Light Modulator) control signal based ontwo-dimensional content; a laser source configured to generate aplurality of incident laser beams based on the laser control signal; aMEMS device configured to receive the plurality of incident laser beamsfrom the laser source; a MEMS controller configured to generate a MEMScontrol signal for the MEMS device and reflect the plurality of incidentlaser beams to a plurality of locations on the LCOS-SLM based on theMEMS control signal; and a LCOS-SLM configured to receive the pluralityof incident laser beams at the plurality of locations, to modulate theplurality of incident laser beams at the plurality of locations based onthe LCOS-SLM control signal, to generate a plurality of holographicwavefronts, each holographic wavefront forming at least one focal point,to generate a plurality of distinct focused light field regions atinterference points of focal points of the plurality of holographicwavefronts, the plurality of distinct focused light field regionscorresponding to the two-dimensional content, and to cure a portion of atarget material at the interference points of the focal points of theplurality of holographic wavefronts.
 2. The holographic printer of claim1, further comprising: a laser source controller coupled to the lasersource, the laser source controller configured to receive the lasercontrol signal and to control the laser source in response to the lasercontrol signal; and a LCOS-SLM controller coupled to the LCOS-SLM, theLCOS-SLM controller configured to receive the LCOS-SLM control signaland to control the LCOS-SLM in response to the LCOS-SLM control signal.3. The holographic printer of claim 1, wherein the dynamic holographyprinting application is configured to: identify a plurality ofpredefined spatial locations corresponding to the two-dimensionalcontent on a layer of the target material adjacent to the LCOS-SLM; andgenerate the LCOS-SLM control signal and the laser control signal toadjust a position of the focal points of the modulated plurality ofincident laser beams to correspond with the plurality of predefinedspatial locations, the LCOS-SLM curing the portion of the targetmaterial at the interference points formed based on the plurality ofpredefined spatial locations.
 4. The holographic printer of claim 1,wherein the dynamic holography printing application is configured to:receive printing data corresponding to the two-dimensional content;identify areas on the surface of the target material based on thetwo-dimensional content; identify a second plurality of focal pointscorresponding to the areas on the surface of the target material basedon the two-dimensional content; and adjust the laser control signal andthe LCOS-SLM control signal based on the second plurality of focalpoints, the areas on the surface of the target material cured at theinterference points based on the second plurality of focal points. 5.The holographic printer of claim 1, wherein the dynamic holographyprinting application is configured to: receive printing datacorresponding to the two-dimensional content; compute a plurality oflocations of interference points based on the two-dimensional content;calculate a plurality of locations of focal points corresponding to theplurality of locations of interference points; generate the lasercontrol signal and the LCOS-SLM control signal to form holographicwavefronts based on the location of the plurality of locations of focalpoints corresponding to the plurality of locations of interferencepoints; heat the target material at the plurality of locations of theinterference points of the holographic wavefronts; and form thetwo-dimensional content at the heated portion of the target material. 6.The holographic printer of claim 1, wherein the LCOS-SLM is configuredto modulate the phase of the plurality of laser light beams, and togenerate the plurality of holographic wavefronts.
 7. The holographicprinter of claim 1, wherein the modulated laser beams includephase-modulated light.
 8. The holographic printer of claim 1, whereinthe dynamic holography printing application is configured to: identify afirst plurality of predefined spatial locations corresponding to a firstportion of the two-dimensional content in the target material adjacentto the LCOS-SLM; adjust the laser control signal and the LCOS-SLMcontrol signal based on the first plurality of predefined spatiallocations; and form a second plurality of the focal points of theplurality of modulated laser light beams based on the first plurality ofpredefined spatial locations, the first portion of the two-dimensionalcontent cured at the interference points based on the second pluralityof focal points on the surface of the target material.
 9. Theholographic printer of claim 8, wherein the dynamic holography printingapplication is configured to: identify a second plurality of predefinedspatial locations corresponding to a second portion of thetwo-dimensional content in the target material; adjust the laser controlsignal and the LCOS-SLM control signal based on the second plurality ofpredefined spatial locations; form a third plurality of the focal pointsof the plurality of modulated laser light beams based on the secondplurality of predefined spatial locations; and form another set ofinterference points based on the third plurality of focal points inaddition to the interference points based on the second plurality offocal points, the second portion of the two-dimensional content cured atthe other set of interference points.
 10. A method of printing usingholographic projection, the method comprising: generating a lasercontrol signal, a MEMS control signal and a LCOS-SLM (Liquid Crystal onSilicon Spatial Light Modulator) control signal based on atwo-dimensional content; generating a plurality of incident laser beamsbased on the laser control signal to a laser source; receiving theplurality of incident laser beams on a MEMS device; reflecting theplurality of incident laser beams to a plurality of locations on theLCOS-SLM based on the MEMS control signal; receiving the plurality ofincident laser beams at the plurality of locations on the LCOS-SLM;modulating the plurality of incident laser beams at the plurality oflocations based on the LCOS-SLM control signal; generating a pluralityof holographic wavefronts from the modulated plurality of incident laserbeams, each holographic wavefront forming at least one correspondingfocal point; generating a plurality of distinct focused light fieldregions at interference points of focal points of the plurality ofholographic wavefronts, the plurality of distinct focused light fieldregions corresponding to the two-dimensional content; and curing aportion of a target material at the interference points of the focalpoints of the plurality of holographic wavefronts.
 11. The method ofclaim 10, further comprising: identifying a plurality of predefinedspatial locations corresponding to the two-dimensional content on thelayer of the target material adjacent to the LCOS-SLM; and generatingthe LCOS-SLM control signal and the laser control signal to adjust aposition of the focal points of the modulated plurality of incidentlaser beams to correspond with the plurality of predefined spatiallocations, the LCOS-SLM curing the portion of the target material at theinterference points formed based on the plurality of predefined spatiallocations.
 12. The method of claim 10, further comprising: receivingprinting data corresponding to the two-dimensional content; identifyingareas on the surface of the target material based on the two-dimensionalcontent; identifying a second plurality of focal points corresponding tothe areas on the surface of the target material based on thetwo-dimensional content; and adjusting the laser control signal and theLCOS-SLM control signal based on the second plurality of focal points,the areas on the surface of the target material cured at theinterference points based on the second plurality of focal points. 13.The method of claim 10, further comprising: receiving printing datacorresponding to the two-dimensional content; computing a plurality oflocations of interference points based on the two-dimensional content;calculating a plurality of locations of focal points corresponding tothe plurality of locations of interference points; generating the lasercontrol signal and the LCOS-SLM control signal to form holographicwavefronts based on the location of the plurality of locations of focalpoints corresponding to the plurality of locations of interferencepoints; irradiating the target material at the plurality of locations ofthe interference points of the holographic wavefronts; and forming thetwo-dimensional content at the irradiated portion of the targetmaterial.
 14. The method of claim 10, further comprising: modulating atleast a phase or an amplitude of the plurality of laser light beams; andgenerating the plurality of holographic wavefronts at the focal points.15. The method of claim 10, further comprising: modulating the pluralityof incident laser beams at the plurality of locations; generating asecond plurality of holographic wavefronts, each holographic wavefrontforming at least one corresponding focal point; and curing a portion ofthe target material at interference points of focal points of the secondplurality of holographic wavefronts.
 16. The method of claim 10, whereinthe modulated laser beams include phase-modulated light.
 17. The methodof claim 10, further comprising: identifying a first plurality ofpredefined spatial locations corresponding to a first portion of thetwo-dimensional content in the target material adjacent to the LCOS-SLM;adjusting the laser control signal and the LCOS-SLM control signal basedon the first plurality of predefined spatial locations; and forming asecond plurality of the focal points of the plurality of modulated laserlight beams based on the first plurality of predefined spatiallocations, the first portion of the two-dimensional content cured at theinterference points based on the second plurality of focal points on thesurface of the target material.
 18. The method of claim 17, furthercomprising: identifying a second plurality of predefined spatiallocations corresponding to a second portion of the two-dimensionalcontent in the target material; adjusting the laser control signal andthe LCOS-SLM control signal based on the second plurality of predefinedspatial locations; forming a third plurality of the focal points of theplurality of modulated laser light beams based on the second pluralityof predefined spatial locations; and forming another set of interferencepoints based on the third plurality of focal points in addition to theinterference points based on the second plurality of focal points, thesecond portion of the two-dimensional content cured at the other set ofinterference points.
 19. A non-transitory computer-readable storagemedium for use with a holographic printer according to claim 1, thecomputer-readable storage medium including instructions that whenexecuted by the hardware processor of the holographic printer, cause theholographic printer to: generate a laser control signal, a MEMS controlsignal and a LCOS-SLM (Liquid Crystal on Silicon Spatial LightModulator) control signal based on a two-dimensional contentcorresponding to a lithography mask; generate a plurality of incidentlaser beams based on the laser control signal to a laser source; receivethe plurality of incident laser beams on a MEMS device; reflect theplurality of incident laser beams to a plurality of locations on theLCOS-SLM based on the MEMS control signal; receive the plurality ofincident laser beams at the plurality of locations on the LCOS-SLM;modulate the plurality of incident laser beams at the plurality oflocations based on the LCOS-SLM control signal; generate a plurality ofholographic wavefronts, each holographic wavefront forming at least onecorresponding focal point; generate a plurality of distinct focusedlight field regions at interference points of focal points of theplurality of holographic wavefronts, the plurality of distinct focusedlight field regions corresponding to the two-dimensional content; andcure a portion of a target material at the interference points of thefocal points of the plurality of holographic wavefronts.